Add a serializable parameter to the cdi-new-bean command

Sometimes it's useful/mandatory to have CDI beans that are serializable. At the moment the cdi-new-bean command doesn't allow us to do that easily (except using scopes that are not always needed). A simple boolean isSerializable could do :

cdi-new-bean --named LoggerProducer --isSerializable

This would generate :

public class LoggerProducer implements Serializable
{
}